I've searched and read everything I could get my eyes on on the matter but nothing completely clarifies this question. I know that CCW is not allowed on CU/UCCS property but what about leaving it in your car while on campus property?

From RMGO:

-School, college, or university grounds.
18-12-105.5. Unlawfully carrying a weapon - unlawful possession of weapons - school, college, or university grounds.
(1) A person commits a class 6 felony if such person knowingly and unlawfully and without legal authority carries, brings, or has in such person's possession a deadly weapon as defined in section 18-1-901 (3) (e) in or on the real estate and all improvements erected thereon of any public or private elementary, middle, junior high, high, or vocational school or any public or private college, university, or seminary, except for the purpose of presenting an authorized public demonstration or exhibition pursuant to instruction in conjunction with an organized school or class, for the purpose of carrying out the necessary duties and functions of an employee of an educational institution that require the use of a deadly weapon, or for the purpose of participation in an authorized extracurricular activity or on an athletic team.
(3) It shall not be an offense under this section if:
(a) The weapon is unloaded and remains inside a motor vehicle while upon the real estate of any public or private college, university, or seminary; or...


 The red text basically says that it's ok to have firearms on campus as long as they are unloaded and in one's vehicle. However, according to the CU Regents:

"NOW THEREFORE BE IT RESOLVED that the possession of the firearms, explosives, or other dangerous or illegal weapons on or within any University of Colorado campus, leased building, other area under the jurisdiction of the local campus police department or areas where such possession interferes with the learning and working environment is prohibited."